Method and system for high speed data links

Abstract

Various embodiments improve the operation of computers by providing methods of transmitting data with low latency and high bandwidth. Data may be transmitted in a packet composed of data flits, the data flits having at least two different formats configured to implement different communication protocols. In some embodiments, a given flit may be transmitted using two different modulation methods, with a first part of the flit transmitted using a first modulation method, such as a binary method, and a second part of the flit using a higher-order modulation method.

What is claimed is: 
     
       1. A method comprising:
 generating a packet comprising a plurality of flits having different formats according to different communication protocols, the packet including a link-level flit having a first format according to a first communications protocol supporting link-level retry and a plurality of end-to-end flits having a second format according to a second communications protocol supporting end-to-end retry, wherein the link-level flit is a header flit identifying the beginning of the contiguous burst of flits, and the packet further comprises:
 a second link-level flit having a third format according to a third communications protocol and formatted as a tail flit to identify the end of the contiguous burst; and 
 
 transmitting the plurality of flits over a communications channel from the transmitter to the receiver in a contiguous burst, the contiguous burst transmitting each of the plurality of flits that define the packet in non-interleaved succession and running the first communications protocol and the second communications protocol simultaneously. 
 
     
     
       2. The method of  claim 1 , wherein the header flit includes:
 a header sideband field storing meta data identifying the link-level flit as the header flit, and a sideband cyclic redundancy check (CRC) field having a CRC value corresponding to the sideband meta data. 
 
     
     
       3. The method of  claim 1 , wherein the end-to-end flit format includes a payload field storing a sub-set of the data, and a freight sideband field identifying the flit as an end-to-end flit. 
     
     
       4. The method of  claim 1 , wherein the tail flit includes a payload field having an end-to-end CRC value for the plurality of end-to-end flits. 
     
     
       5. The method of  claim 1 , wherein transmitting the plurality of flits from the transmitter to the receiver in the contiguous burst comprises transmitting the plurality of flits over a single virtual channel. 
     
     
       6. The method of  claim 1 , further comprising checking flit integrity of at least one flit of the plurality of flits at a point in the communications channel between the transmitter and the receiver, and requesting the transmitter to resend the flit if the flit integrity is not verified. 
     
     
       7. A system comprising:
 one or more processors; and 
 a memory communicably coupled to the one or more processors and including instructions that when executed by the one or more processors cause the one or more processors to: 
 generate a packet comprising a plurality of flits having different formats according to different communication protocols, the packet including a link-level flit having a first format according to a first communications protocol supporting link-level retry and a plurality of end-to-end flits having a second format according to a second communications protocol supporting end-to-end retry, wherein the link-level flit is a header flit identifying the beginning of the contiguous burst of flits, and the packet further comprises:
 a second link-level flit having a third format according to a third communications protocol and formatted as a tail flit to identify the end of the contiguous burst; and 
 transmit the plurality of flits over a communications channel from the transmitter to the receiver in a contiguous burst, the contiguous burst transmitting each of the plurality of flits that define the packet in non-interleaved succession. 
 
 
     
     
       8. The system of  claim 7 , wherein the header flit includes:
 a header sideband field storing meta data identifying the link-level flit as the header flit, and a sideband cyclic redundancy check (CRC) field having a CRC value corresponding to the sideband meta data. 
 
     
     
       9. The system of  claim 7 , wherein the end-to-end flit format includes a payload field storing a sub-set of the data, and a freight sideband field identifying the flit as an end-to-end flit. 
     
     
       10. The system of  claim 7 , wherein the tail flit includes a payload field having an end-to-end CRC value for the plurality of end-to-end flits. 
     
     
       11. The system of  claim 7 , wherein the instruction to transmit the plurality of flits from the transmitter to the receiver in the contiguous burst comprises transmitting the plurality of flits over a single virtual channel. 
     
     
       12. The system of  claim 7 , further comprising checking flit integrity of at least one flit of the plurality of flits at a point in the communications channel between the transmitter and the receiver, and requesting the transmitter to resend the flit if the flit integrity is not verified. 
     
     
       13. A non-transitory computer-readable medium for self-supervised scale-aware learning of camera extrinsic parameters and storing instructions that when executed by one or more processors cause the one or more processors to:
 generate a packet comprising a plurality of flits having different formats according to different communication protocols, the packet including a link-level flit having a first format according to a first communications protocol supporting link-level retry and a plurality of end-to-end flits having a second format according to a second communications protocol supporting end-to-end retry wherein the link-level flit is a header flit identifying the beginning of the contiguous burst of flits, and the packet further comprises:
 a second link-level flit having a third format according to a third communications protocol and formatted as a tail flit to identify the end of the contiguous burst; and 
 
 transmitting the plurality of flits over a communications channel from the transmitter to the receiver in a contiguous burst, the contiguous burst transmitting each of the plurality of flits that define the packet in non-interleaved succession and transmitting the plurality of flits over a single virtual channel. 
 
     
     
       14. The non-transitory computer-readable medium of  claim 13 , wherein the header flit includes:
 a header sideband field storing meta data identifying the link-level flit as the header flit, and a sideband cyclic redundancy check (CRC) field having a CRC value corresponding to the sideband meta data. 
 
     
     
       15. The non-transitory computer-readable medium of  claim 13 , wherein the end-to-end flit format includes a payload field storing a sub-set of the data, and a freight sideband field identifying the flit as an end-to-end flit. 
     
     
       16. The non-transitory computer-readable medium of  claim 13 , wherein the tail flit includes a payload field having an end-to-end CRC value for the plurality of end-to-end flits. 
     
     
       17. The non-transitory computer-readable medium of  claim 13 , wherein transmitting the plurality of flits from the transmitter to the receiver in the contiguous burst comprises running the first communications protocol and the second communications protocol simultaneously. 
     
     
       18. The non-transitory computer-readable medium of  claim 13 , further comprising checking flit integrity of at least one flit of the plurality of flits at a point in the communications channel between the transmitter and the receiver, and requesting the transmitter to resend the flit if the flit integrity is not verified.